Method and apparatus for heating and cooling substrates

ABSTRACT

A method and apparatus for heating and cooling a substrate are provided. A chamber is provided that comprises a heating mechanism adapted to heat a substrate positioned proximate the heating mechanism, a cooling mechanism spaced from the heating mechanism and adapted to cool a substrate positioned proximate the cooling mechanism, and a transfer mechanism adapted to transfer a substrate between the position proximate the heating mechanism and the position proximate the cooling mechanism.

[0001] This application is a continuation of U.S. patent applicationSer. No. 10/073,762, filed Feb. 11, 2002, which is a continuation ofU.S. patent application Ser. No. 09/909,915, filed Jul. 20, 2001, whichis a division of U.S. Pat. No. 6,276,072 B1, issued Aug. 21, 2001, whichis a continuation-in-part of U.S. Pat. No. 6,182,376 B1, issued Feb. 6,2001, all of which are hereby incorporated by reference herein in theirentirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to semiconductor devicemanufacturing and more specifically to a method and apparatus forheating and cooling substrates.

BACKGROUND OF THE INVENTION

[0003] Semiconductor wafers, flat panel displays and other similarsubstrates typically have numerous material layers deposited thereonduring device fabrication. Some commonly deposited layers (e.g., spin-onglass (SOG) films) may contain contaminants, defects of undesirablemicrostructures that can be reduced in number or altogether removed byheating or “annealing” the substrate at an appropriate temperature foran appropriate time. Other deposited layers (e.g., copper films) mayhave properties that undesirably change over time or “self-anneal”,resulting in unpredictable deposited layer properties (e.g.,unpredictable resistivity, stress, grain size, hardness, etc.). As withcontaminants, defects and undesirable microstructures, deposited layerproperties often can be stabilized by a controlled annealing step (e.g.,for copper films, a 200-400° C., 15 second 3 minute anneal in a gas suchas N₂ or about 96% N₂, 4% H₂). Following any annealing step, a substratepreferably is rapidly cooled so that other processes can be performed onthe substrate without delay (i.e., to increase throughput).

[0004] Conventionally annealing is performed within a quartz furnacethat must be slowly pre-heated to a desired annealing temperature, orwithin a rapid thermal process (RTP) system that can be rapidly heatedto a desired annealing temperature. Thereafter an annealed substrate istransferred to a separate cooling module which conventionally employs acooled substrate support and is slightly backfilled with a gas such asargon to enhance thermal conduction. The separate cooling moduleincreases equipment cost and complexity, as well as equipment footprint,and decreases substrate throughput by requiring substrate transfer timebetween the heating and cooling systems. Accordingly, a need exists foran improved method and apparatus for heating and cooling substrates thatis less expensive, less complex, and has a reduced equipment footprintand increased throughput when compared to conventional substrate heatingand cooling systems.

SUMMARY OF THE INVENTION

[0005] To overcome the needs of the prior art, an inventive chamber isprovided that allows for rapid heating and cooling of a substrate withina single chamber. As no transfer time to a separate cooling module isrequired, the invention decreases equipment cost, complexity andfootprint while increasing substrate throughput. Specifically, theinventive chamber includes a heating mechanism adapted to heat asubstrate positioned proximate the heating mechanism, a coolingmechanism spaced from the heating mechanism and adapted to cool asubstrate positioned proximate the cooling mechanism, and a transfermechanism adapted to transfer a substrate between a position proximatethe heating mechanism and a position proximate the cooling mechanism. Asused herein “proximate” means close enough to affect sufficient thermalenergy transfer for either heating or cooling a substrate. The heatingmechanism and the cooling mechanism preferably are separated by about 1to 5 inches.

[0006] The heating mechanism preferably comprises a heated substratesupport adapted to support a substrate and to heat the supportedsubstrate to a predetermined temperature, and the cooling mechanismpreferably comprises a cooling plate (e.g., a water cooled cooling plateor a refrigerant cooled cooling plate). A plurality of holes may beprovided within the cooling plate that allow a gas to flow through thecooling plate (so as to cool the gas) before the gas strikes asubstrates positioned proximate the cooling plate.

[0007] The transfer mechanism transfers a substrates from a positionproximate the heating mechanism to a position proximate the coolingmechanism, and preferably employs only single-axis, linear motion so asto further reduce equipment complexity and cost. The transfer mechanismmay comprise, for example, a wafer lift hoop having a plurality offingers adapted to support a substrate, or a plurality of wafer liftpins. A dry gas source may be coupled to the chamber in order to supplya dry gas thereto. The chamber includes a pump adapted to evacuate thechamber to a predetermined pressure (e.g., about 20 and 200 Torr) duringcooling, as the present inventors have found that a reduced chamberpressure provides good thermal conduction for short distances (so that asubstrate positioned proximate the cooling mechanism is cooled thereby)but poor thermal conduction for large distances (so that a substratebeing cooled by being positioned proximate the cooling mechanism is notalso heated by the distantly located heating mechanism).

[0008] As is apparent from the above description, the invention providesa method for efficiently heating (e.g., annealing, degassing, etc.) andcooling a substrate within a single chamber. Wafer transfer time isreduced, footprint is reduced and simpler wafer movements are employed.

[0009] Other objects, features and advantages of the present inventionwill become more fully apparent from the following detailed descriptionof the preferred embodiments, the appended claims and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a side elevational view of a heating and coolingapparatus configured in accordance with the invention;

[0011]FIG. 2 is a top elevational view of the substrate support of theheating and cooling apparatus of FIG. 1;

[0012]FIG. 3 is a graph of wafer temperature versus time for variouscooling conditions within the heating and cooling apparatus of FIG. 1;

[0013]FIG. 4 is a graph of wafer temperature versus time during atypical annealing and cooling process within the heating and coolingapparatus of FIG. 1; and

[0014]FIG. 5 is a top plan view of a fabrication tool that employs theinventive heating and cooling apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015]FIG. 1 is a side elevational view of a heating and coolingapparatus 11 configured in accordance with the present invention. Inorder to conveniently describe the inventive apparatus 11, itscomponents will be described with reference to an object to be heatedand cooled. However, it will be understood that the object itself is nota part of the apparatus.

[0016] As shown in FIG. 1, the heating and cooling apparatus 11comprises a chamber 13 containing a heated substrate support if (e.g., asubstrate support having a resistive heating element 15 d therein). Thechamber 13 preferably has a small volume of about 5 20 liters to allowfor rapid evacuation of the chamber (described below) and reducedprocess gas consumption. The heated substrate support 15 may compriseany conventional heated substrate support (e.g., a stainless steelsubstrate support) having a temperature range sufficient for the processto be performed (typically about 150-600° C. for most annealingapplications). A gas inlet 17 couples a dry gas source 19 (such as anoble gas or nitrogen, preferably 100% N₂ having fewer than a few partsper million of O₂ therein, or 4% or less of H₂ diluted in N₂ and havingfewer than a few parts per million of O₂ therein) to the chamber 13. Thegas emitted from the dry gas source 19 may be further “dried” via agetter or cold trap (not shown) within the gas inlet 17. A gas outlet 21couples the chamber 13 to a vacuum pump 23 which, in operation, pumpsgas from the chamber 13.

[0017] A semiconductor wafer 25 may be placed directly on the heatedsubstrate support 15, or optionally, a plurality of pins 27 (preferably3-6 pins, most preferably three pins 27 a-c as shown in FIGS. 1 and 2)which extend from the substrate support 15, support the wafer 25 so asto facilitate gas flow along the backside of the wafer 25 and so as toreduce contact between the wafer 25 and the substrate support 15(thereby reducing particle generation by such contact). Short pinheights facilitate heat transfer from the substrate support 15 to thewafer 25; preferably the pins 27 a-c are between 0.005-0.02 inches inheight. The positioning of the plurality of pins 27 can be seer withreference to FIG. 2 which shows the heated substrate support 15 from atop plan view. To improve substrate temperature uniformity duringheating, the diameter of the heated substrate support is preferably islarger than the diameter of the substrate being heated (e.g., a nineinch substrate support is preferred for heating an eight inchsubstrate). The heated substrate support 15 heats the wafer 25 primarilyby conduction (e.g., either direct contact conduction if a substratetouches the heated substrate support 15 or conduction through a dry gassuch as nitrogen disposed between the substrate support 15 and asubstrate when the substrate rests on the pins 27). A convective heatingcomponent also may be employed if gas is flowed along the backside ofthe wafer 25 during heating. However, the addition of a convectiveheating component, such as a backside gas flow, during substrate heatinghas been found to have minimal impact on heating time due to the shortheating times typically employed (e.g., about 15 seconds to a fewminutes) and the small gap between the wafer 25 and the heated substratesupport 15 (e.g., 0.005-0.02 inches). The use of a backside gas glowalso may require wafer clamping (e.g., via a partial/full clamp ring orvia an electrostatic chuck as are known in the art) so as to preventwafer movement due to the gas flow.

[0018] In order to easily place a wafer on and extract a wafer from theheated substrate support 15, a conventional 3-6 finger wafer lift hoop29 (the operation of which is well known in the art) or the like isemployed. The wafer list hoop 29 extends and retracts from the substratesupport 15 (e.g., via a servo or stepper motor) and is of the typehaving at least three fingers (represented by reference numbers 29 a-c),that extend under the edge of the wafer 25. Thus, during wafer liftingand lowering, wafer contact is limited to the area above the threefingers 29 a-c, and fewer particles are generated. The specific detailsof the preferred configuration for the fingers 29 a-c are described inparent application, U.S. Pat. No. 6,182,376 B1, issued Feb. 6, 2001.Alternatively the pins 27 a-c may be motorized so as to extend andretract to and from the substrate support 15. Preferably the waferlifting mechanism (e.g., the lift hoop 29 or the pins 27) extend andretract between a position proximate the substrate support 15 and aposition proximate the cooling plate 39.

[0019] The rate at which the gas flows into the chamber 13 is controlledvia a needle valve or flow controller 35 (e.g., a mass flow controller)operatively coupled along the gas inlet 17. Preferably, the vacuum pump23 comprises a rough-pump, such as a dry pump, having a pumping speed ofbetween about 1-50 liters/sec for rapid evacuation of the chamber 13.The gas outlet 21 comprises an isolation valve 37, such as a pneumaticroughing port valve, operatively coupled to the vacuum pump 23 so as tocontrol the gas flow rate from thc chamber 13 and preferably a chamberexhaust valve 38 for use during chamber purging. Because a rough pump iscapable of evacuating a chamber to a pressure of a few milliTorr orhigher, a rough pump alone may be employed for applications wherein theheating and cooling apparatus 11 is not evacuated below a pressure of afew milliTorr (e.g., when the heating and cooling apparatus 11 is usedas a stand-alone module that is vented to atmospheric pressure with anon-oxidizing gas such as nitrogen prior to loading a substrate thereinor when a substrate is transferred directly between the heating andcooling apparatus 11 and other process chambers that employ pressures ofa few milliTorr or higher). However, for applications that requirepressures below a few milliTorr (e.g., pressures which cannot beobtained with a rough pump alone, a high vacuum pump (not shown) such asa cryopump also may be employed to allow substrate transfer between ahigh vacuum environment and the chamber 13 (e.g., when using the heatingand cooling apparatus 11 with a fabrication tool as described below withreference to FIG. 5 or when otherwise directly transferring a substratebetween the heating and cooling apparatus 11 and other process chambersthat employ pressures below a few milliTorr).

[0020] To affect rapid cooling of the wafer 25 following wafer heatingwithin the chamber 13 (described below), a water or refrigerant cooledcold plate 39 (e.g., an aluminum cooling plate that may be cooled toabout 5 to 25° C. by a cooling fluid supplied from a cooling fluidsource 40) is disposed within the heating and cooling apparatus 11distant the heated substrate support 15 (e.g., preferably about 15inches therefrom). Because the substrate support 15 and the cold plate39 preferably are disposed opposite one another, only single-axis,linear motion (e.g., less expensive and less complex motion thanmulti-axis motion) need be employed to transfer a substratetherebetween. In fact, the wafer lift mechanism (e.g., the wafer lifthoop 29 or the pins 27) may be configured to transfer a wafer betweenthe position proximate the substrate support 15 and the cooling plate39.

[0021] The cold plate 39 preferably employs a diffuser or shower headdesign as known in the art, having up to ten thousand 0.02-0.1 inchdiameter holes therein (represented by reference numbers 39 a-n in FIG.1). The holes 39 a-n allow gas to flow through the cold plate 39 (e.g.,from the dry gas source 19) and to thereby be cooled by the cold plate39 so as to improve cooling of the wafer 25 as described below. Thewalls of the chamber 13 preferably are water or refrigerant (e.g., a 50%de-ionized wafer/50% glycol solution having a freezing point below thatof pure water) cooled as well to further enhance substrate cooling.

[0022] As shown in FIG. 1, the gas inlet 17 is positioned adjacent theheated substrate support 15. However, the gas inlet 17 couldalternatively be coupled to the upper portion of the chamber 13 (asshown in phantom) to supply dry gas to the holes 39 a-n of the coldplate 39 and/or to a manifold (not shown) having a plurally of openingswhich diffuse gas emitted from the gas inlet 17 into the chamber 13 andcause a substantially uniform flow of dry gas over the wafer 25'sfrontside. The design of such a manifold is well known to Those ofordinary skill in the art of CVD reactor design.

[0023] U.S. Pat. No. 4,854,263 entitled “Inlet Manifold and Method forIncreasing Gas Dissociation and for PECVD of Dielectric Films” isincorporated herein by this reference, for it teaching of a specificinlet manifold.

[0024] Note that because the inventive heating and cooling apparatus 11employs only a single chamber and employs relatively inexpensivecomponents (e.g., the heated substrate support 15, the wafer cooledcooling plate 39, preferably single-axis, linear motion for transferringa substrate therebetween, etc), heating and cooling is economicallyperformed with reduced footprint and increased throughput as the needfor substrate transfer time to a separate cooling module is eliminated.A controller C is coupled to the various chamber components (e.g., theheated substrate support 15, the wafer lift mechanism 27 or 29, the flowcontroller 35, the isolation valve 37, the chamber exhaust valve 38, thecooling fluid source 40, the chamber isolation slit valve 41 and thetransfer station wafer handler 43 a) and is programmed so as to causethe inventive chamber to perform the inventive method described below.

[0025] In operation, prior to placing a wafer 25 within the chamber 13,the chamber 13 is pre-conditioned. For example, the substrate support 15may be pre-heated to a desired heating temperature (e.g., for annealingor degassing purposes) and the cold plate 39 may be pre-cooled to adesired cooling temperature. Additionally, to pre-condition the chamber13 to a predetermined contamination level (e.g., so that less than 10parts per million O₂ resides in the chamber 13) the chamber 13 may bepurged at atmospheric pressure by flowing dry gas from the dry gassource 19 into the chamber 13 with the chamber exhaust valve 38 open,may be single-evacuation purged by evacuating the chamber 13 topredetermined vacuum level via the rough pump 23 (by opening anisolation valve 37 coupled therebetween) and then back filling thechamber 13 with dry gas from the dry gas source 19, or may be cyclepurged by repeatedly evacuating the chamber 13 to a predetermined vacuumlevel and then back filling the chamber 13 with dry gas from the dry gassource 19 to further reduce contamination levels beyond those achievableby atmospheric pressure or single evacuation purging.

[0026] As an example for a copper anneal within the chamber 13, thesubstrate support is heated to between about 150-600° C., and morepreferably to between about 200-400° C., and the cold plate is cooled tobetween about 5 and 25° C., more preferably to about 15° C. Copper filmsreadily oxidize, particularly at elevated temperatures such as thoseemployed during annealing, and form undesirable copper oxide regionsthat degrade film resistivity and increase the contact resistance ofinterconnects fabricated therefrom. Accordingly, the chamber 13'senvironment preferably is pre-conditioned to contain less than about 10parts per million of oxygen For example by purging or cycle purging thechamber with a dry gas from the dry gas source 19 that comprises N₂having only a few parts per million of oxygen, and more preferably about96% N₂ with 4% H₂ having only a few parts per million of oxygen, as asmall amount of H₂ suppresses oxide formation.

[0027] After the chamber 13 is pre-conditioned, a chamber isolation slitvalve 41 that couples the chamber 13 to a station for loading a waferinto or unloading a wafer from the chamber 13 (i.e., a transfer station43) opens and a transfer station wafer handler 43 a extendstherethrough, carrying the wafer 25 into position above the heatedsubstrate support 15. The transfer station 43 typically in atatmospheric pressure (preferably a nitrogen or other non-oxidizingatmosphere such as an argon atmosphere) and may be constantly purgedwith nitrogen or any other non-oxidizing gas to reduce the concentrationof oxygen that enters the chamber 13 during wafer transfer.Alternatively the transfer station 43 may be at a reduced chamberpressure (e.g., if the heating and cooling apparatus and/or the transferstation 43 is coupled to other process chambers employing reducedpressures) that preferably has a low oxygen partial pressure.

[0028] The opening of the slit valve 41 preferably is no larger than theminimum area required to move the wafer 25 and the blade of the waferhandler 43 a into or out of the chamber 13, thereby minimizing theimpact of the transfer station 43's atmosphere on the chamber 13'satmosphere. To prevent contaminants (e.g., oxygen during copper filmannealing) from entering the chamber 13 as the wafer 25 is transferredthereto, the chamber 13 may be purged with dry gas from the dry gassource wafer 19 wafer (typically at a flow rate of about wafer 5-100s.l.m) during wafer transfer. This is particularly important when thetransfer stations 43's atmosphere is not clean (e.g., has a high oxygenconcentration or other high impurity concentration that may affect thewafer 25 or films formed thereon during heating or cooling within thechamber 13). The wafer lift hoop 29 (via the three fingers 29 a-c) liftsthe wafer 25 from the transfer station wafer handler 43 a and after thetransfer station wafer handler 43 a has sufficiently retracted, the slitvalve 41 closes and the wafer lift hoop 29 lowers the wafer onto theheated substrate support 15. Preferably the wafer 25 is in directcontact with the substrate support 15 (or with the pins 27 a-c) so as tomaximize heat transfer therebetween and to minimize wafer heating time.The pressure within the chamber 13 preferably is maintained at aboutatmospheric pressure in a non-oxidizing gas such as nitrogen either bycooling the chamber 13 from the rough pump 23 (via the isolation valve37), or by purging the chamber 13 with dry gas with the chamber exhaustvalve 38 open or while pumping the chamber 13 with the rough pump 23.Note that the gas pressure within the chamber 13 aids in the transfer ofheat from the heated substrate support 15 to the wafer 25 as describedin parent application, U.S. Pat. No. 6,182,376 B1, issued Feb. 6, 2001.Chamber pressures of a few Torr or less yield a poor heat conductionpath between the wafer 25 and the heated substrate support 15. Thus awafer backside gas preferably is employed at such reduced chamberpressures (e.g., an argon, helium or nitrogen backside gas withappropriate wafer clamping to prevent wafer movement caused by thebackside gas).

[0029] An anneal, degas or other heating process thereafter may beemployed on the wafer 25 using the substrate support 15. For example, acopper anneal may be performed by maintaining the wafer 25 in contactwith the substrate support 15 for about 15 seconds to 3 minutes,depending on the temperature of the heated substrate support 15 and thedesired anneal, degas or other heating process duration. To perform adegas process with the heating and cooling apparatus 11 such as theinventive degas process described in parent application, U.S. Pat. No.6,182,376 B1, issued Feb. 6, 2001, a cryopump or other high vacuum pumppreferably is provided in addition to or in place of the rough pump 23to obtain the low pressures (e.g., 1×10⁻⁵ Torr) required thereof.

[0030] Following an annealing, degas or other heating process, the waferlift hoop 29 elevates, raising the wafer 25 above the heated substratesupport 15 to a position proximate the cold plate 39 so as to cool thewafer 25. As described below with reference to FIG. 3, to optimize thecooling rate of the wafer 25, the gap between the top surface of thewafer 25 and the bottom surface of the cold plate 39 preferably is lessthan about 0.02″ or about 0.5 mm, the pressure within the chamber 13preferably is reduced to between about 20 200 Torr during cooling, anddry gas from the dry gas source 19 may be flowed (e.g., at a rate ofabout 100-150 s.l.m.) through the cold plate 39 (e.g., via the holes 39a-n) to generate a cool dry gas that strikes the top surface of thewafer 25.

[0031]FIG. 3 is a graph of wafer temperature versus time for the variouschamber 13 cooling conditions listed in TABLE 1 (below). To obtain thedata plotted in these graphs, the substrate support 15 was heated to atemperature of 350° C. (e.g., to simulate a heating process performedjust prior to a cooling process), the cold plate 39 was cooled to atemperature of 25° C. and the distance between the substrate support 15and the cold plate 39 was about 40 mm. Wafers were held in directcontact with the heated substrate support 15 without employing the pins27 a-c. TABLE 1 CURVE # COOLING CONDITIONS 301 1. 150 s.l.m. N₂ purgethrough cold plate holes    39a-n; 2. Chamber pressure of about 760Torr; and    3. 3 mm wafer-cold plate distance. 302 1. 150 s.l.m. N₂purge through cold plate holes    39a-n; 2. Chamber pressure of about 80Torr; 3. 3 mm wafer-cold plate distance. 303 1. 150 s.l.m. N₂ purgethrough cold plate holes    39a-n; 2. 10 s.l.m. N₂ purge on backside ofwater; 3. Chamber pressure of about 760 Torr; 4. 3 mm wafer-cold platedistance. 304 1. No N₂ flow; 2. Chamber pressure of about 760 Torr; 3.0.25 mm water-cold plate distance. 305 1. No N₂ flow; 2. Chamberpressure of about 47 Torr; 3. 0.45 mm wafer-cold plate distance.

[0032] As can be seen with joint reference to FIG. 3 and TABLE 1, for afixed wafer to-cold plate distance (e.g., 3 mm for curves 301-303),reducing the pressure within the chamber 13 and flowing dry gas (e.g.,N₂) through the holes 39 a-n of the cold plate 39, as well as to thebackside of the wafer 25, increases the cooling rate of the wafer 25.However, the distance between the wafer 25 and the cold plate 39 withoptimized chamber pressure plays a more significant role in cooling awater than flowing a cool dry gas as shown by curve 304 which representsthe cooling achieved with no N₂ purge through cold plate holes 39 a-n, a0.25 mm wafer-cold plate distance, and a 700 Torr chamber pressure; andby curve 305 which represents the cooling achieved with no N₂ purgethrough cold plate holes 39 a-n, a 0.45 mm wafer-cold plate distance,and a 47 Torr chamber pressure.

[0033] Specifically, the present inventors have found that reducedchamber pressures (e.g., about 20-200 Torr) during cooling optimize thecooling process because reduced presource continue to provide goodthermal conduction for a small distance (e.g., less than 0.5 mm) betweenthe wafer 25 and the cold plate 39. At the same time, reduced chamberpressures have been found to suppress heat transfer from the heatedsubstrate support 15 to the wafer 25 which are preferably separated byabout 25-125 mm (e.g., about 25-125 mm between the substrate support 15and the cold plate 39). As can be seen from FIG. 3, cooling from 350° C.can require as much as about 20 seconds depending on the coolingconditions employed, but can be reduced to about 5 seconds for optimalcooling conditions (e.g., a chamber pressure of 47 Torr and a 0.45 mmwafer-cold plate distance). As can be seen by the differences betweencurves 301 and 302, the addition of a convective cooling component byflowing a gas through the cooling plate holes 39 a-n has less of animpact on cooling than does reducing heat conduction between the heatedsubstrate support 15 and the wafer 25 during cooling. As with heating,cooling appears to be predominately conduction dominated.

[0034] Following the cooling process, the chamber 13 is vented with drygas from the dry gas source 19 to a pressure of about 760 Torr (1atmosphere) or is evacuated to a pressure required for wafer transferinto a fabrication system (as described below with reference to FIG. 5).The chamber isolation slit valve 41 opens and the transfer station waferhandler 43 a reaches into the chamber 13 and extends under the wafer 25.Thereafter the wafer lift hoop 29 lowers (transferring the wafer 25 tothe wafer handler 43 a) and the wafer handler 43 a retracts carrying thewafer 25 into the transfer station 43. To prevent contaminants from thetransfer station 43 from entering the chamber 13 as the wafer 25 istransferred therefrom, the chamber 13 may be purged continuously withdry gas from the dry gas source 19 (typically at a flow rate of about5-100 s.l.m.) while the slit valve 41 is open. After the wafer handler43 a retracts from the chamber 13 the slit valve 41 closes, and purging(if any) of the chamber 13 may be halted.

[0035]FIG. 4 is a graph of wafer temperature versus time during atypical annealing and cooling process within the heating and coolingapparatus 11 of FIG. 1. The substrate support 15 is pre-heated to atemperature of 340° C., the cold plate 39 is pre-cooled to a temperatureof 25° C. and the chamber 13 is pre-conditioned to contain less thanabout 10 parts per million of oxygen (e.g., by purging or cycle purgingthe chamber 13 as previously described). The chamber 13 preferably isbackfilled with a dry gas such as nitrogen to a pressure of about 760Torr. With reference to FIG. 4, at time 1, the wafer 25 is placeddirectly on the heated substrate support 15 (without employing the pins27 a-c) via the wafer lift hoop 29, and between times 1 and 2 annealingis performed (e.g., at a chamber pressure of about 760 Torr). At time 2,the wafer 25 is lifted from the heated substrate support 15 via thewafer lift hoop 29, and at time 3 arrives at a position proximate thecold plate 39 (e.g., about 0.45 mm from the cold plate 39), beginningthe wafer cooling cycle. At time 4, the rough pump 23 begins pumping thechamber 13. Pumping continues until time 5 when the pressure within thechamber 13 reaches about 47 Torr. Once the chamber pressure reachesabout 47 Torr, the wafer 25 begins to cool rapidly (between times 5 and6). At time 6 the cooling process ends and the chamber 13 is vented toatmospheric pressure with dry gas (e.g., N₂) from the dry gas source 19(or is evacuated as described below with reference to FIG. 5). At time 7the chamber isolation slit valve 41 opens and the wafer 25 is extractedfrom the chamber 13 as previously described. Note that it desired, thechamber 13 may be pumped by the rough pump 23 prior to time 4 (e.g.,during wafer transfer from the substrate support 15 to the cooling plate39). However, the present inventors have found that cooling is moreefficient (e.g., is factor) when pumping of the chamber 13 is notperformed until the wafer 25 has reached the cooling plate 39.

[0036] The heating and cooling apparatus 11 may be used as a stand alongheating and cooling system, separate from a fabrication system thatcouples multiple process chambers, or may be used as part of afabrication system. For example, FIG. 5 is a top plan view of afabrication system 45 that employs the inventive heating and coolingapparatus of FIG. 1. The fabrication system 45 comprises at least afirst load lock 47, at least one process chamber 49, at least one waferhandler 51 and the inventive heating and cooling apparatus 11. The atleast one wafer handler 51 resides within a transfer chamber 53 thatcouples the first load lock 47, the process chamber 49 and the inventiveheating and cooling apparatus 11.

[0037] In operation, a wafer carrier containing at least one wafer isloaded into the first load lock 47, and the first load lock 47 is pumpedto a desired vacuum level, typically set by the process to be performedwithin the process chamber 49 (e.g., slightly below atmospheric pressurefor a subatmospheric CVD process such so low k dielectric deposition, ata low pressure for a PVD process, etc.). If the inventive heating andcooling chamber 11 is to be employed for annealing only, the waferhandler 51 extracts a first wafer from the first load lock 47 andtransports it to the process chamber 49. An annealable process (e.g.,low k dielectric film deposition, etc.) is performed on the wafer andthe wafer is transferred via the wafer handler 51 to the inventiveheating and cooling apparatus 11. A sealable port such as the slit valve41 (FIG. 1A) on the chamber 13 opens allowing the wafer handler 51 toreach into the chamber 13 and deposit the first wafer on the heatedsubstrate support 15, as previously described. The wafer handler 51retracts and the slit valve 41 closes. The wafer is then heated andcooled in accordance with the invention as described with reference toFIGS. 1-4. After heating and cooling, the wafer is returned to the firstload lock 47. The sequence repeats until each wafer within the wafercarrier has been processed and returned to the first load lock 47.

[0038] If the inventive heating and cooling chamber 11 is to be employedfor degassing, the above sequence is reversed. Each wafer travels fromthe first load lock 47 to the inventive heating and cooling apparatus 11and is degassed therein. Thereafter each wafer travels from theinventive heating and cooling apparatus 11 to the process chamber 49,has a process performed thereon, and then travels from the processchamber 49 to the first load lock 47 (either directly or after having acooling step or an annealing and cooling step performed thereon withinthe heating and cooling apparatus 11). Note that many processes thatrequire a degassing step also require a high vacuum level (e.g., PVDprocesses). Accordingly, the heating and cooling apparatus 11 mayrequire a cryopump in addition to a rough pump so as to reach the highvacuum level (as set by the process chamber wafer 49) required for thefabrication system 45.

[0039] The foregoing description discloses only the preferredembodiments of the invention, modifications of the above disclosedapparatus and method which fall within the scope or the invention willbe readily apparent to those of ordinary skill in the art. For instance,although the components of the inventive heating and cooling apparatusand the configurations described herein are presently preferred,numerous variations may occur and yet remain within the scope of theinvention. For example, heating may be performed in an upper or firstside portion of the chamber 13 and cooling in a lower or second sideportion of the chamber 13. The needle valve or flow controller and theisolation valves can be manually adjusted but are preferably computercontrolled. The substrate support 15 may be resistively heated, heatedby lamps (e.g., infrared lamps inside or outside of the chamber 13),heated from underneath or directly, or heated via any other knownheating mechanism.

[0040] A substrate may be heated by either touching the substratesupport 15 or merely by being held proximate the substrate support 15.Similarly, a substrate may be cooled by either touching the cold plate39, or merely by being held in close proximity to the cold plate 39. Acooled substrate support or other cooling mechanism may be employed inplace of the cold plate 39. Heating and/or cooling may be performed witha chamber pressure at or slightly above atmospheric pressure or with areduced chamber pressure, with or without gas flowing through the coldplate 39.

[0041] The wafer lift mechanism may be motorized, pneumatic or employany other known lifting mechanism (e.g., a wafer handler such as thewafer handler 43 a). The wafer may be heated and then transferred viathe lift mechanism to a supporting mechanism position proximate thecooling mechanism. One such supporting mechanism and transfer processthereto is disclosed in U.S. Pat. No. 5,951,770, issued Sep. 14, 1999,the entire disclosure of which is incorporated herein by this reference.Further, numerous objects other than wafers (for example liquid crystaldisplay panels and glass plates) may benefit from the inventive process.In addition to nitrogen, any other non-oxidizing gas such as argon,helium, etc., may form all or part of the chamber 13's atmosphere duringsubstrate heating, cooling and/or transfer or during chamber idle.

[0042] Accordingly, while the present invention has been disclosed inconnection with the preferred embodiments thereof, it should beunderstood that other embodiments may fall within the spirit and scopeof the invention, as defined by the following claims.

The invention claimed is:
 1. A fabrication system comprising: a processchamber; a heating and cooling chamber including: a heating mechanismadapted to heat a substrate positioned proximate the heating mechanism;a coolable member spaced from the heating mechanism and adapted to coola substrate positioned proximate the coolable member, the coolablemember being coolable by a cooling mechanism; and a transfer mechanismadapted to transfer a substrate between a position proximate the heatingmechanism and a position proximate the coolable member; and a substratehandler adapted to transfer a substrate between the process chamber andthe heating and cooling chamber.
 2. The system of claim 1 wherein theprocess chamber is adapted to deposit a copper film.
 3. The system ofclaim 2 wherein the heating and cooling chamber is adapted to perform acopper anneal process.
 4. The system of claim 1 wherein the heating andcooling chamber is adapted to perform a copper anneal process.
 5. Thesystem of claim 1 wherein the heating mechanism comprises a heatedsubstrate support.
 6. The system of claim 5 wherein the heated substratesupport is adapted to support a substrate and to heat the supportedsubstrate to a predetermined temperature.
 7. The system of claim 1wherein the heating mechanism and the coolable member are separated byabout 1 to 5 inches.
 8. The system or claim 1 wherein the coolablemember comprises a cooling plate,
 9. The system of claim 8 wherein thecooling plate comprises a cooling plate selected from the groupconsisting of a wafer cooled cooling plate and a refrigerant cooledcooling plate.
 10. The system of claim 8 wherein the cooling platecomprises a plurality of holes adapted to allow a gas to flow throughthe cooling plate so as to cool the gas.
 11. The system of claim 8wherein the cooling plate may be cooled to between about 5 and 25° C.12. The system of claim 1 wherein the transfer mechanism comprises aplurality of wafer lift pins.
 13. The system of claim 1 wherein thetransfer mechanism is adapted to transfer a substrate positionedproximate the heating mechanism to a position of less than about 0.02inches from the coolable member.
 14. The system of claim 1 furthercomprising a dry gas source coupled to the heating and cooling chamberand adapted to supply a dry gas thereto.
 15. The system of claim 14wherein the dry gas comprises a dry gas selected from the groupconsisting of approximately 100% N₂ and approximately 96% or greater N₂with 4% or less H₂, both having less than about 5 parts per million ofO₂.
 16. The system of claim 14 wherein the coolable member comprises aplurality of holes adapted to allow a gas to flow through the coolablemember so as to cool the gas and wherein the dry gas source is coupledto the coolable member and is adapted to supply a dry gas that flowsthrough the plurality of holes of the coolable member.
 17. The system ofclaim 14 further comprising a manifold having a plurality of holesadapted to allow a gas to flow through the manifold so as to diffuse thegas and wherein the dry gas source is coupled to the manifold and isadapted to supply a dry gas that flows through the manifold.
 18. Thesystem of claim further comprising a pump coupled to the heating andcooling chamber and adapted to evacuate the heating and cooling chamberto a predetermined pressure.
 19. The system of claim 18 having acontroller coupled thereto, the controller being programmed to cause thepump to evacuate the heating and cooling chamber to a predeterminedpressure during cooling of a substrate with the coolable member.
 20. Thesystem of claim 19 wherein the predetermined pressure is between about20 and 200 Torr.
 21. The system of claim 1 wherein the transfermechanism is adapted to transfer a substrate between a positionproximate the heating mechanism and a position proximate the coolablemember by employing single-axis, linear motion.
 22. A fabrication systemcomprising: a process chamber adapted to perform a deposition process ona substrate; a heating and cooling chamber adapted to perform a copperanneal process on a substrate processed within the process chamber, theheating and cooling chamber including: a heating mechanism adapted toheat a substrate positioned proximate the heating mechanism; a coolablemember spaced from the heating mechanism and adapted to cool a substratepositioned proximate the coolable member, the coolable member beingcoolable by a cooling mechanism; and a transfer mechanism adapted totransfer a substrate between a position proximate the heating mechanismand a position proximate the coolable member; and a substrate handleradapted to transfer a substrate between the process chamber and theheating and cooling chamber.
 23. The system of claim 22 wherein theprocess chamber is adapted to deposit a copper film.
 24. A methodcomprising: (a) providing a fabrication system having: a processchamber; a heating and cooling chamber including: a heating mechanismadapted to heat a substrate positioned proximate the heating mechanism;a coolable member spaced from the heating mechanism and adapted to coola substrate positioned proximate the coolable member, the coolablemember being coolable by a cooling mechanism; and a transfer mechanismadapted to transfer a substrate between a position proximate the heatingmechanism and a position proximate the coolable member; and a substratehandler adapted to transfer a substrate between the process chamber andthe heating and cooling chamber; (b) processing a substrate within theprocess chamber; (c) transferring the substrate from the process chamberto the heating and cooling chamber; and (d) annealing the substratewithin the heating and cooling chamber.
 25. The method of claim 24wherein step (d) comprises performing & copper anneal process.
 26. Themethod of claim 25 further comprising cooling the substrate within theheating and cooling chamber.
 27. A method comprising: (a) providing afabrication system having: a process chamber adapted to perform adeposition process on a substrate; a heating and cooling chamberincluding: a heating mechanism adapted to heat a substrate positionedproximate the heating mechanism; a coolable member spaced from theheating mechanism and adapted to cool a substrate positioned proximatethe coolable member, the coolable member being coolable by a coolingmechanism; and a transfer mechanism adapted to transfer a substratebetween a position proximate the heating mechanism and a positionproximate the coolable member; and a substrate handler adapted totransfer a substrate between the process chamber and the heating andcooling chamber; (b) performing a deposition process on a substratewithin the process chamber; (c) transferring the substrate from theprocess chamber to the heating and cooling chamber; and (d) performing acopper annealing process on the substrate within heating and coolingchamber.
 28. The method of claim 27 wherein step (b) comprisesperforming a copper deposition process on the substrate.
 29. The methodof claim 27 further comprising cooling the substrate within the heatingand cooling chamber.
 30. A method of heating and cooling a substratecomprising: (a) providing a fabrication system having: a processchamber; a heating and cooling chamber including: a heating mechanismadapted to heat a substrate positioned proximate the heating mechanism;a coolable member spaced from the heating mechanism and adapted to coola substrate positioned proximate the coolable member, the coolablemember being coolable by a cooling mechanism; and a transfer mechanismadapted to transfer a substrate between a position proximate the heatingmechanism and a position proximate the coolable member; and a substratehandler adapted to transfer a substrate between the process chamber andthe heating and cooling chamber; (b) processing the substrate within theprocess chamber; (c) transferring the substrate from the process chamberto the heating and cooling chamber; (d) positioning the substrate at aposition proximate the heating mechanism; (e) heating the substrate withthe heating mechanism; (f) transferring the substrate from the positionproximate the heating mechanism to a position proximate the coolablemember; and (g) cooling the substrate with the coolable member.
 31. Themethod of claim 30 wherein step (b) comprises performing a copperdeposition process.
 32. The method of claim 30 wherein one or more ofsteps (d)-(g) comprise performing a copper anneal process.
 33. Themethod of claim 30 wherein positioning the substrate proximate theheating mechanism comprises placing the substrate on a heated substratesupport.
 34. The method of claim 30 wherein transferring the substratefrom a position proximate the heating mechanism to a position proximatethe coolable member comprises transferring the substrate from a positionproximate the heating mechanism to a position proximate a cooling plate.35. The method of claim 30 wherein transferring the substrate from aposition the heating mechanism to a position proximate the coolablemember comprises transferring the substrate from a position proximatethe heating mechanism to a position less than about 0.02 inches from thecoolable member.
 36. The method of claim 30 wherein cooling thesubstrate with the coolable member comprises cooling the substrate withthe coolable member having a temperature between about 5 and 25° C. 37.The method of claim 30 further comprising flowing a dry gas into theheating and cooling chamber during at least one of heating and coolingthe substrate.
 38. The method of claim 30 further comprising flowing adry gas through a plurality of holes within the coolable member duringcooling the substrate.
 39. The method of claim 30 further comprisingevacuating the chamber to a predetermined pressure during cooling thesubstrate.
 40. The method of claim 39 wherein evacuating the chamber toa predetermined pressure during cooling the substrate comprisesevacuating the chamber to between about 20 and 200 Torr during coolingthe substrate.
 41. The method of claim 30 wherein heating the substratewith the heating mechanism comprises annealing the substrate.
 42. Themethod of claim 30 wherein heating the substrate with the heatingmechanism comprises degassing the substrate.
 43. The method of claim 30wherein transferring the substrate from the position proximate theheating mechanism to the position proximate the coolable membercomprises transferring the substrate by employing single-axis, linearmotion.